Treozen
Junior Member
- Joined
- Dec 26, 2022
- Posts
- 4
- Reaction score
- 1
- Location
- Washington
- First Name
- Allan
- Truck Year
- 1978
- Truck Model
- C20
- Engine Size
- 454
Hello folks -
I recently purchased a 1978 C20 Camper Special (2wD) with the 454, and she needs some things. One of those things, is new tires, and so perfect opportunity for new wheels.
I've been "doing the math" and a lot of reading about what fits, but much of the calculation depends on what is on there now. I know the tire is a 9.5 R16.5 - which is basically equivalent in height and width to a 235/80/16 (Radius 30.6, width 9.5 vs 30.8 and 9.3) So I've been using the 253/80/16 as my baseline. When measuring for clearance changes, I need to know if the stock 16.5 wheel is 6" or 6.5", and does it have 4" backspace? I've read posts from several sites that conflict - some say its a 6" rim, others 6.5 and other sites suggest 7". Backspacing is suggested at 4" , but again, conflicting data.
I could go pull a wheel off, but that requires going outside....and well....its cold out there, plus its dark. Who knows what's lurking around. Does anyone have a definitive stock wheel width and backspace for the 1978 C20 16.5 rim?
Thanks - and although you've clearly seen one before, the obligatory picture of the truck:
I recently purchased a 1978 C20 Camper Special (2wD) with the 454, and she needs some things. One of those things, is new tires, and so perfect opportunity for new wheels.
I've been "doing the math" and a lot of reading about what fits, but much of the calculation depends on what is on there now. I know the tire is a 9.5 R16.5 - which is basically equivalent in height and width to a 235/80/16 (Radius 30.6, width 9.5 vs 30.8 and 9.3) So I've been using the 253/80/16 as my baseline. When measuring for clearance changes, I need to know if the stock 16.5 wheel is 6" or 6.5", and does it have 4" backspace? I've read posts from several sites that conflict - some say its a 6" rim, others 6.5 and other sites suggest 7". Backspacing is suggested at 4" , but again, conflicting data.
I could go pull a wheel off, but that requires going outside....and well....its cold out there, plus its dark. Who knows what's lurking around. Does anyone have a definitive stock wheel width and backspace for the 1978 C20 16.5 rim?
Thanks - and although you've clearly seen one before, the obligatory picture of the truck: